Visakha Dairy — I bought tetra pack milk cost of 13 rs its not expired but milk was curdled

Address:

Aarilova,14-461,small kirana shop

I want my 13 rupees I bought milk packet it still not expired but milk was curdled I take it back to the shop but they was not replaced or paid back any money, because if I opened the milk packet it was not replaceable, but without opened that milk packet how should I know it was wasted or not